Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,427 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 135.102.0.0/16 | 65.5k | ARIN |  US | 30th Apr 1996 |
| 135.104.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.107.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.108.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.110.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.113.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.124.0.0/16 | 65.5k | ARIN | US | 11th Oct 2000 |
| 135.128.0.0/16 | 65.5k | ARIN | US | 6th Jan 1994 |
| 135.132.128.0/20 | 4.1k | ARIN | US | 27th Jan 2026 |
| 135.137.0.0/16 | 65.5k | ARIN | US | 6th Jan 1994 |
| 135.138.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.139.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.141.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.142.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.143.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.144.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.15.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.150.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.152.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.154.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.155.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.156.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.157.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.158.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.16.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.160.0.0/13 | 524k | ARIN | US | 30th Apr 1996 |
| 135.168.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.17.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.170.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.172.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.176.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.182.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.184.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.186.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.188.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.192.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.198.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.2.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.208.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.21.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.210.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.212.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.214.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.215.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.216.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.217.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.218.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.219.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.24.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.242.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |